For the past ten years I have ridden in a flat area of the country. I found that it was very easy to go out and ride 50-100 miles with very little effort providing the wind wasn't blowing in your face. Now, everywhere I look there are hills ranging in little elevation gain - 25 feet elevation gain up to 200 feet in rise climbs. The inclines went from ranging 2-4% in grade now to 5% up to 15% grade and I have seen it hit 20 on one of my rides. Is there a comparision to find out where I am at for the year. ie- 50 miles of flats is like 30 miles of constant rollers? Just curious, because I come off these rides tired. When I was riding flats, I knew I had ridden, but I had tons more energy.